Almost two decades ago the Philippine government closed U.S. military bases in the country. However in 1999 an agreement allowed hundreds of U.S. troops to return to train Philippine soldiers to fight Islamic militants and Maoist insurgents.
There are about 600 U.S. Special Forces in the Philippines mostly used to help target a militant Islamic group said to be linked to Al Qaeda. The former government of Gloria Arroyo was cited in leaked Wikileaks cables for extrajudicial killings and false arrests. The U.S. is to provide over 163 million in aid in 2012.
The U.S. government is talking to the new Philippine government about establishing a larger military presence in the Philippines. These actions are all part of U.S. plans to extend its military power further into the area to counter Chinese influence.
The U.S. is also expanding its military presence in Australia and Singapore with troops and bases. For more see this article.